Pfizer and Adolor Corp. have signed an exclusive collaboration to develop and commercialize novel compounds, ADL5859 and ADL5747, for the treatment of pain. Both compounds are proprietary Delta opioid receptor agonist candidates with the potential to treat a wide range of inflammatory, neuropathic and acute pain conditions.

The companies will form a Joint Steering Committee to guide the development and commercialization of products resulting from the collaboration. Pfizer will be responsible for securing regulatory approvals and commercialization on a worldwide basis.

The terms of the agreement provide for Pfizer and Adolor to share revenues and expenses 60/40 in the U.S. Outside the U.S., Pfizer will fund development activities and, upon commercialization, Adolor will receive royalties on Pfizer net sales. Adolor will receive an upfront, non-refundable payment of $30 million, plus $1.9 million reimbursement for prior Phase II development costs. Adolor may also receive payments of as much as $232.5 million upon the achievement of development and regulatory milestones for its Delta compounds. More than 50% of these milestones may be earned prior to regulatory approval of the compounds, with the first milestone payment available to be earned on commencement of Phase IIb clinical studies.

“We are pleased to be partnering with Pfizer in this very exciting program,” said Michael R. Dougherty, president and chief executive officer of Adolor Corporation. “Our vision for the Delta agonists has been to develop a new class of opioids, delivering analgesia without some of the complicating side effects of traditional mu agonists. Pfizer brings extensive pain management development and commercial expertise to this collaboration and we look forward to working with Pfizer in the pursuit of this vision.”

ADL5859 is in a Phase II development program exploring analgesic efficacy in inflammatory pain associated with rheumatoid arthritis and acute post-dental surgery pain. Additional programs are planned to evaluate ADL5859 in patients with diabetic peripheral neuropathy and osteoarthritis. All future development work is subject to a Joint Development Committee. Adolor expects to begin Phase I clinical testing of ADL5747 in the first quarter of 2008.

“This collaboration demonstrates our commitment to executing against the R&D plan we outlined, including expanding our Phase II portfolio with a strong focus in our key therapeutic areas,” said Dr. Martin Mackay, president of Pfizer Global R&D. “Pfizer has a strong history in bringing to market novel pain solutions including Lyrica, Neurontin and Celebrex. However, there still remains a significant unmet medical need for patients suffering from a variety of debilitating pain conditions.”